1. Technical Field
The present invention relates to an image display apparatus and a head-mounted display.
2. Related Art
For example, as an image display apparatus for displaying an image on a screen, there is a known configuration including a light source and an optical scanner that deflects light from the light source for two-dimensional scanning (see JP-A-2008-304726, for example).
The image display apparatus described in JP-A-2008-304726 includes a plurality of semiconductor lasers, a parallelizing lens that parallelizes a laser light flux from each of the semiconductor lasers, a polarizing beam splitter that combines the plurality of laser light fluxes, and a MEMS (optical scanner) that deflects the combined laser light flux from the polarizing beam splitter for two-dimensional scanning. A mirror provided in the MEMS is disposed to be perpendicular to a plane including the optical axis of the laser light flux from each of the semiconductor lasers, and the mirror is irradiated with the laser light flux traveling in a direction inclined to a normal to the mirror. In JP-A-2008-304726, the configuration described above is intended to reduce the size of the apparatus.
In the image display apparatus described in JP-A-2008-304726, the mirror is resonantly driven to swing in the in-plane direction in the plane at a large amplitude, whereas driven to swing in an out-of-plane direction (direction perpendicular to the plane) at an amplitude smaller than the amplitude in the in-plane direction. Since laser light LL is incident on the mirror in a direction inclined in the in-plane direction to a normal to the mirror as described above, the large amplitude of the mirror in the in-plane direction disadvantageously greatly distorts two ends of a drawable region S, which is a region of a screen, a wall surface, or any other object that can be scanned with the laser light, as shown in FIG. 8B, resulting in a decrease in area of a rectangular effective drawing region (region actually irradiated with laser light for image display) S′ provided in the drawable region S. As a result, efficient laser light scanning cannot be made, or excellent image display characteristics cannot be achieved.
That is, the image display apparatus described in
JP-A-2008-304726 is problematic in that reduction in size of the apparatus and provision of excellent image display characteristics cannot be achieved at the same time.